FIGS. 1A and 1B show a conventional optical connector fabricated by the transfer molding of an epoxy resin. FIG. 1A is a perspective view of the connector before the connection, and FIG. 1B shows an end face of the connector.
An optical connector ferrule 20 molded from epoxy resin has optical fiber guide holes 21 and two guide pin holes 22 formed in its interior. The guide holes 21 are used to fix, in proper alignment, coated optical fibers A after the coating layer of an end portion is stripped to expose the individual fibers. In order to connect these optical fibers, they are inserted into the guide holes 21 and fixed in proper axial alignment. Thereafter, two guide pins 23 are inserted the respective pin holes 22.
In the optical connector, as shown in FIGS. 1A and 1B, which connects optical fibers in proper axial alignment by inserting guide pins into respective pin holes, it is necessary that the bore diameter of each pin hole 22 be greater than the outside diameter of the guide pin 23.
However, if the clearance (g) between the bore diameter of the pin hole 22 and the outside diameter of the guide pin 23 is excessive, optical fibers cannot be connected with high precision of positioning. In particular, when the optical fibers to be connected are single-mode optical fibers having a core diameter of only about 9-10 .mu.m or dispersion-shifted optical fibers having a core diameter less than the single-mode optical diameter, it is very difficult to accomplish low-loss and consistent connection of the optical fibers.
Therefore, it is necessary to produce the guide pin holes and guide pins with extremely high dimensional accuracy in its bore diameter and outer diameter, respectively. However, the production cost increases and considerable skill is required to accomplish connecting operations in a consistent way.